1,425 research outputs found
The impact of extreme storm surges on Mid-Atlantic coastal forests
The Mid-Atlantic coastal forests in Virginia are stressed by episodic disturbance from storms associated with hurricanes and nor'easters. Using annual tree ring data, we adopt a dendroclimatic and statistical modelling approach to understand the response and resilience of a coastal pine forest to slow progressive climate change and extreme storm surge events. Results indicate that radial growth of trees in the study area is influenced by age, vigor, competition, microsite variability, and regional climatic trends, but dominated periodically by disturbance due to storm surges. We evaluated seven local storm surge events to understand the effect of storm surges associated with nor'easters and hurricanes on radial growth. A general decline in radial growth was observed in the year of the storm and three years following it, after which the radial growth starts recovering. Given the projected increase in hurricanes and storm surge severity with changing global climate, this study contributes to understanding declining tree growth response and resilience of coastal forests to past disturbances. This can help predict vegetation response patterns to similar disturbances in the future
Development Of A MATLAB-based Structural Analysis Toolbox For Sensor Placement In A Multi-domain Physical System
This paper discusses a Bond Graph (BG) Structural Analysis Toolbox developed in MATLAB® (MATSAT) that performs causal analysis on the BG and assists the user in the sensor selection process for a multi-domain physical system. MATSAT contains modules for performing the Sequential Causality Assignment Procedure (SCAP) and Causal Path Search (CaPS). The modules can be combined to check for structural properties such as structural observability (SO) for any sensor set. The working of MATSAT is shown for standard systems. Verification of SCAP, CaPS, and necessary and sufficient SO conditions is shown
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Provider Awareness Alone Does Not Improve Transition Readiness Skills in Adolescent Patients With Inflammatory Bowel Disease
ABSTRACT Objective: Adolescent patients with chronic health conditions must gradually assume responsibility for their health. Self-management skills are needed for a successful transfer from adolescent to adult health care, but the development of these skills could be resource intensive. Pediatric providers are already instrumental in teaching patients about their health and may improve these skills. The aim of the study was to evaluate whether informal education of pediatric providers regarding transition improves inflammatory bowel disease (IBD) patient self-management skills. Methods: Consecutive patients with IBD older than 10 years who presented to the outpatient setting were administered a survey regarding self-management behaviors in 2008 and 2011. During this time, several conferences on transition were presented to the providers. Results: In 2008, 294 patients completed the survey (82%) compared with 121 patients (89%) in 2011. The patient groups were comparable with respect to sex (boys 50% vs 42%), mean age (16.7 vs 16.2 years), and type of IBD (Crohn 68% vs 66%). The 13- to 15-year-olds reported calling in refills (11%, 8%, respectively), scheduling clinic appointment (0, 1%), preparing questions (13%, 5%), and taking the main role in talking during clinic visits (15%, 24%). The 16- to 18-year-olds reported calling in refills (13%, 27%), scheduling clinic appointments (9%, 6%), preparing questions (9%, 16%), and taking the main role in talking in clinic visits (36%, 45%). Responsibility for behaviors gradually increases with age, but did not differ significantly between 2008 and 2011. Conclusions: Increasing awareness around transition readiness for pediatric providers had an insignificant effect on the self-management skills of patients with IBD. A more formal or structured approach is likely required to improve transition skills in adolescent patients
Producer services and trade liberalization
Trade liberalization and recent advances in communication and information technologies increasingly permit the trade of producer services across borders. This entry discusses research on the nature and importance of such trade, and on the consequences of services trade liberalization. Trade in producer services now accounts for close to 70% of services trade and 14% of total world trade. Services trade liberalization has figured prominently in multilateral negotiations in the World Trade Organization and in many regional trade agreements. Progress in liberalizing services trade has been slow, however, and has been achieved mainly via unilateral initiatives. As a consequence, important barriers remain across many countries and types of services. This is despite the fact that a small but growing body of research has shown that trade liberalization in producer services can have substantial positive economic effects
The SOPHIE search for northern extrasolar planets. II. A multi-planet system around HD9446
We report the discovery of a planetary system around HD9446, performed from
radial velocity measurements secured with the spectrograph SOPHIE at the 193-cm
telescope of the Haute-Provence Observatory during more than two years. At
least two planets orbit this G5V, active star: HD9446b has a minimum mass of
0.7 M_Jup and a slightly eccentric orbit with a period of 30 days, whereas
HD9446c has a minimum mass of 1.8 M_Jup and a circular orbit with a period of
193 days. As for most of the known multi-planet systems, the HD9446-system
presents a hierarchical disposition, with a massive outer planet and a lighter
inner planet.Comment: 7 pages, 6 figures, 3 tables, accepted for publication in A&
External asymmetries in the Euro area and the role of foreign direct investment
Soon after the introduction of the common currency, a divide emerged between two groups in
the Euro area: one comprised of the North-European countries achieving external surpluses
and the other of the South-European countries with large external deficits. This paper shows
that different patterns of Foreign Direct Investment (FDI) inflows across the Euro area
countries contributed to this divergence. Our theoretical framework shows that if the
economy is relatively capital-intensive in the production of traded (non-traded) output, FDI
will be channeled in greater proportions to the traded (non-traded) sector, thus improving
(deteriorating) the trade balance. Focusing on ten Euro area countries over the period 1980-
2009, we establish a positive (negative) long-run effect of FDI inflows on the trade balance in
the North (South). In the North the positive effect stems from the traded-sector FDI inflows
that were significantly higher in comparison to the South, both before and after the EMU. In
contrast, in the South the increased FDI inflows in the post-EMU era were dominated by
investments in the non-traded sector. When industry-level data are employed, a positive
(negative) long-run effect of manufacturing (non-manufacturing) FDI inflows on the trade
balance in the North (South) is further established
SPIDER VII - Revealing the Stellar Population Content of Massive Early-type Galaxies out to 8Re
Radial trends of stellar populations in galaxies provide a valuable tool to
understand the mechanisms of galaxy growth. In this paper, we present the first
comprehensive analysis of optical-optical and optical-NIR colours, as a
function of galaxy mass, out to the halo region (8Re) of early-type galaxies
(ETGs). We select a sample of 674 massive ETGs (M*>3x10^10MSun) from the
SDSS-based SPIDER survey. By comparing with a large range of population
synthesis models, we derive robust constraints on the radial trends in age and
metallicity. Metallicity is unambiguously found to decrease outwards, with a
measurable steepening of the slope in the outer regions (Re<R<8Re). The
gradients in stellar age are found to be more sensitive to the models used, but
in general, the outer regions of ETGs feature older populations compared to the
cores. This trend is strongest for the most massive galaxies in our sample
(M*>10^11MSun). Furthermore, when segregating with respect to large scale
environment, the age gradient is more significant in ETGs residing in higher
density regions. These results shed light on the processes leading from the
formation of the central core to the growth of the stellar envelope of massive
galaxies. The fact that the populations in the outer regions are older and more
metal-poor than in the core suggests a process whereby the envelope of massive
galaxies is made up of accreted small satellites (i.e. minor mergers) whose
stars were born during the first stages of galaxy formation.Comment: 20 pages, 13 figures, 10 tables. Accepted for publication in MNRA
Galaxy Zoo: Passive Red Spirals
We study the spectroscopic properties and environments of red spiral galaxies
found by the Galaxy Zoo project. By carefully selecting face-on, disk dominated
spirals we construct a sample of truly passive disks (not dust reddened, nor
dominated by old stellar populations in a bulge). As such, our red spirals
represent an interesting set of possible transition objects between normal blue
spirals and red early types. We use SDSS data to investigate the physical
processes which could have turned these objects red without disturbing their
morphology. Red spirals prefer intermediate density regimes, however there are
no obvious correlations between red spiral properties and environment -
environment alone is not sufficient to determine if a spiral will become red.
Red spirals are a small fraction of spirals at low masses, but are a
significant fraction at large stellar masses - massive galaxies are red
independent of morphology. We confirm that red spirals have older stellar popns
and less recent star formation than the main spiral population. While the
presence of spiral arms suggests that major star formation cannot have ceased
long ago, we show that these are not recent post-starbursts, so star formation
must have ceased gradually. Intriguingly, red spirals are ~4 times more likely
than normal spirals to host optically identified Seyfert or LINER, with most of
the difference coming from LINERs. We find a curiously large bar fraction in
the red spirals suggesting that the cessation of star formation and bar
instabilities are strongly correlated. We conclude by discussing the possible
origins. We suggest they may represent the very oldest spiral galaxies which
have already used up their reserves of gas - probably aided by strangulation,
and perhaps bar instabilities moving material around in the disk.Comment: MNRAS in press, 20 pages, 15 figures (v3
Observation of the full 12-hour-long transit of the exoplanet HD80606b. Warm-Spitzer photometry and SOPHIE spectroscopy
We present new observations of a transit of the 111-day-period exoplanet
HD80606b. Using the Spitzer Space Telescope and its IRAC camera on the
post-cryogenic mission, we performed a 19-hour-long photometric observation of
HD80606 that covers the full transit of 13-14 January 2010. We complement this
photometric data by new spectroscopic observations that we simultaneously
performed with SOPHIE at Haute-Provence Observatory. This provides radial
velocity measurements of the first half of the transit that was previously
uncovered with spectroscopy. This new data set allows the parameters of this
singular planetary system to be significantly refined. We obtained a
planet-to-star radius ratio R_p/R_* = 0.1001 +/- 0.0006 that is slightly lower
than the one measured from previous ground observations. We detected a feature
in the Spitzer light curve that could be due to a stellar spot. We also found a
transit timing about 20 minutes earlier than the ephemeris prediction; this
could be caused by actual TTVs due to an additional body in the system or by
underestimated systematic uncertainties. The sky-projected angle between the
spin-axis of HD80606 and the normal to the planetary orbital plane is found to
be lambda = 42 +/- 8 degrees thanks to the fit of the Rossiter-McLaughlin
anomaly. This allows scenarios with aligned spin-orbit to be definitively
rejected. Over the twenty planetary systems with measured spin-orbit angles, a
few of them are misaligned; this is probably the signature of two different
evolution scenarios for misaligned and aligned systems, depending if they
experienced or not gravitational interaction with a third body. As in the case
of HD80606b, most of the planetary systems including a massive planet are
tilted; this could be the signature of a separate evolution scenario for
massive planets in comparison with Jupiter-mass planets.Comment: 14 pages, 9 figures, 2 tables, accepted for publication in A&
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